Identify which instantiator can work (close #34)

tck/src/org/objenesis/tck/search/ClassEnumerator.java

@@ -0,0 +1,117 @@
+/**
+ * Copyright 2006-2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.objenesis.tck.search;
+
+import java.io.File;
+import java.io.IOException;
+import java.net.URL;
+import java.util.ArrayList;
+import java.util.Enumeration;
+import java.util.List;
+import java.util.jar.JarEntry;
+import java.util.jar.JarFile;
+
+/**
+ * Taken and adapted from <a href="https://raw.githubusercontent.com/ddopson/java-class-enumerator/master/src/pro/ddopson/ClassEnumerator.java">here</a>
+ *
+ * @author Henri Tremblay
+ */
+public class ClassEnumerator {
+
+    private static Class<?> loadClass(String className) {
+        try {
+            return Class.forName(className);
+        }
+        catch (ClassNotFoundException e) {
+            throw new RuntimeException("Unexpected ClassNotFoundException loading class '" + className + "'");
+        }
+    }
+
+    private static void processDirectory(File directory, String pkgname, List<Class<?>> classes) {
+
+        // Get the list of the files contained in the package
+        String[] files = directory.list();
+
+        for (int i = 0; i < files.length; i++) {
+            String fileName = files[i];
+            // we are only interested in .class files
+            if (fileName.endsWith(".class")) {
+                // removes the .class extension
+                String className = pkgname + '.' + fileName.substring(0, fileName.length() - 6);
+                classes.add(loadClass(className));
+                continue;
+            }
+
+            File subdir = new File(directory, fileName);
+            if (subdir.isDirectory()) {
+                processDirectory(subdir, pkgname + '.' + fileName, classes);
+            }
+        }
+    }
+
+    private static void processJarfile(URL resource, String pkgname, List<Class<?>> classes) {
+        String relPath = pkgname.replace('.', '/');
+        String resPath = resource.getPath();
+        String jarPath = resPath.replaceFirst("[.]jar[!].*", ".jar").replaceFirst("file:", "");
+
+        JarFile jarFile;
+        try {
+            jarFile = new JarFile(jarPath);
+        } catch (IOException e) {
+            throw new RuntimeException("Unexpected IOException reading JAR File '" + jarPath + "'", e);
+        }
+        Enumeration<JarEntry> entries = jarFile.entries();
+        while(entries.hasMoreElements()) {
+            JarEntry entry = entries.nextElement();
+            String entryName = entry.getName();
+            String className = null;
+            if(entryName.endsWith(".class") && entryName.startsWith(relPath) && entryName.length() > (relPath.length() + "/".length())) {
+                className = entryName.replace('/', '.').replace('\\', '.').replace(".class", "");
+            }
+
+            if (className != null) {
+                classes.add(loadClass(className));
+            }
+        }
+    }
+
+    public static List<Class<?>> getClassesForPackage(Package pkg) {
+        List<Class<?>> classes = new ArrayList<Class<?>>();
+
+        String pkgname = pkg.getName();
+        String relPath = pkgname.replace('.', '/');
+
+        // Get a File object for the package
+        Enumeration<URL> resources;
+        try {
+            resources = ClassLoader.getSystemClassLoader().getResources(relPath);
+        } catch (IOException e) {
+            throw new RuntimeException(e);
+        }
+
+        while(resources.hasMoreElements()) {
+            URL resource = resources.nextElement();
+            if (resource.toString().startsWith("jar:")) {
+                processJarfile(resource, pkgname, classes);
+            } else {
+                processDirectory(new File(resource.getPath()), pkgname, classes);
+            }
+        }
+
+        return classes;
+    }
+
+}

tck/src/org/objenesis/tck/search/SearchWorkingInstantiator.java

@@ -0,0 +1,66 @@
+/**
+ * Copyright 2006-2015 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.objenesis.tck.search;
+
+import org.objenesis.instantiator.ObjectInstantiator;
+
+import java.io.Serializable;
+import java.lang.reflect.Constructor;
+import java.lang.reflect.InvocationTargetException;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+/**
+ * This class will try every available instantiator on the platform to see which works.
+ *
+ * @author Henri Tremblay
+ */
+public class SearchWorkingInstantiator implements Serializable { // implements Serializable just for the test
+
+    @SuppressWarnings("unchecked")
+    public static void main(String[] args) throws Exception {
+        List<Class<?>> classes = ClassEnumerator.getClassesForPackage(ObjectInstantiator.class.getPackage());
+        Collections.sort(classes, new Comparator<Class<?>>() {
+            public int compare(Class<?> o1, Class<?> o2) {
+                return o1.getSimpleName().compareTo(o2.getSimpleName());
+            }
+        });
+
+        for (int i = 0; i < classes.size(); i++) {
+            Class<?> c = classes.get(i);
+            if(c.isInterface() || !ObjectInstantiator.class.isAssignableFrom(c)) {
+                continue;
+            }
+
+            Constructor<?> constructor = c.getConstructor(Class.class);
+
+            String result;
+            try {
+                ObjectInstantiator<SearchWorkingInstantiator> instantiator =
+                        (ObjectInstantiator<SearchWorkingInstantiator>) constructor.newInstance(SearchWorkingInstantiator.class);
+                instantiator.newInstance();
+                result = "Working!";
+            }
+            catch(Exception e) {
+                Throwable t = (e instanceof InvocationTargetException) ? e.getCause() : e;
+                result = "KO - " + t;
+            }
+
+            System.out.printf("%-50s: %s%n", c.getSimpleName(), result);
+        }
+    }
+}